Simple Priority SMP Scheduler

Simple Priority SMP Scheduler. More...

Files
file	schedulersimplesmp.h
	Simple SMP Scheduler API.
file	schedulersimplesmp.c
	Simple SMP Scheduler Implementation.

Data Structures
struct	Scheduler_simple_SMP_Context

Macros
#define	SCHEDULER_SIMPLE_SMP_MAXIMUM_PRIORITY   255
#define	SCHEDULER_SIMPLE_SMP_ENTRY_POINTS
	Entry points for the Simple SMP Scheduler. More...

Functions
void	_Scheduler_simple_SMP_Initialize (const Scheduler_Control *scheduler)
	Initializes the scheduler's context. More...
void	_Scheduler_simple_SMP_Node_initialize (const Scheduler_Control *scheduler, Scheduler_Node *node, Thread_Control *the_thread, Priority_Control priority)
	Initializes the node with the given attributes. More...
void	_Scheduler_simple_SMP_Block (const Scheduler_Control *scheduler, Thread_Control *thread, Scheduler_Node *node)
	Blocks a thread. More...
void	_Scheduler_simple_SMP_Unblock (const Scheduler_Control *scheduler, Thread_Control *thread, Scheduler_Node *node)
	Unblocks a thread. More...
void	_Scheduler_simple_SMP_Update_priority (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Updates the priority of the node. More...
bool	_Scheduler_simple_SMP_Ask_for_help (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Asks for help. More...
void	_Scheduler_simple_SMP_Reconsider_help_request (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Reconsiders help. More...
void	_Scheduler_simple_SMP_Withdraw_node (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node, Thread_Scheduler_state next_state)
	Withdraws node. More...
void	_Scheduler_simple_SMP_Add_processor (const Scheduler_Control *scheduler, Thread_Control *idle)
	Adds idle to scheduler. More...
Thread_Control *	_Scheduler_simple_SMP_Remove_processor (const Scheduler_Control *scheduler, struct Per_CPU_Control *cpu)
	Removes an idle thread from the given cpu. More...
void	_Scheduler_simple_SMP_Yield (const Scheduler_Control *scheduler, Thread_Control *thread, Scheduler_Node *node)

Detailed Description

Simple Priority SMP Scheduler.

The Simple Priority SMP Scheduler allocates a processor for the processor count highest priority ready threads. The thread priority and position in the ready chain are the only information to determine the scheduling decision. Threads with an allocated processor are in the scheduled chain. After initialization the scheduled chain has exactly processor count nodes. Each processor has exactly one allocated thread after initialization. All enqueue and extract operations may exchange threads with the scheduled chain. One thread will be added and another will be removed. The scheduled and ready chain is ordered according to the thread priority order. The chain insert operations are O(count of ready threads), thus this scheduler is unsuitable for most real-time applications.

The thread preempt mode will be ignored.

Macro Definition Documentation

SCHEDULER_SIMPLE_SMP_ENTRY_POINTS

#define SCHEDULER_SIMPLE_SMP_ENTRY_POINTS

Value:

{ \
    _Scheduler_simple_SMP_Initialize, \
    _Scheduler_default_Schedule, \
    _Scheduler_simple_SMP_Yield, \
    _Scheduler_simple_SMP_Block, \
    _Scheduler_simple_SMP_Unblock, \
    _Scheduler_simple_SMP_Update_priority, \
    _Scheduler_default_Map_priority, \
    _Scheduler_default_Unmap_priority, \
    _Scheduler_simple_SMP_Ask_for_help, \
    _Scheduler_simple_SMP_Reconsider_help_request, \
    _Scheduler_simple_SMP_Withdraw_node, \
    _Scheduler_default_Pin_or_unpin, \
    _Scheduler_default_Pin_or_unpin, \
    _Scheduler_simple_SMP_Add_processor, \
    _Scheduler_simple_SMP_Remove_processor, \
    _Scheduler_simple_SMP_Node_initialize, \
    _Scheduler_default_Node_destroy, \
    _Scheduler_default_Release_job, \
    _Scheduler_default_Cancel_job, \
    _Scheduler_default_Tick, \
    _Scheduler_SMP_Start_idle \
    SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY \
  }

Entry points for the Simple SMP Scheduler.

Function Documentation

_Scheduler_simple_SMP_Add_processor()

void _Scheduler_simple_SMP_Add_processor	(	const Scheduler_Control *	scheduler,
		Thread_Control *	idle
	)

Adds idle to scheduler.

Parameters

[in,out]	scheduler	The scheduler instance to add the processor to.
	idle	The idle thread control.

_Scheduler_simple_SMP_Ask_for_help()

bool _Scheduler_simple_SMP_Ask_for_help	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Asks for help.

Parameters

scheduler	The scheduler instance to ask for help.
the_thread	The thread needing help.
node	The scheduler node.

Return values

true	Ask for help was successful.
false	Ask for help was not successful.

_Scheduler_simple_SMP_Block()

void _Scheduler_simple_SMP_Block	(	const Scheduler_Control *	scheduler,
		Thread_Control *	thread,
		Scheduler_Node *	node
	)

Blocks a thread.

Parameters

	scheduler	The scheduler instance.
[in,out]	thread	The thread to block.
[in,out]	node	The scheduler node of thread.

_Scheduler_simple_SMP_Initialize()

void _Scheduler_simple_SMP_Initialize

(

const Scheduler_Control *

scheduler

)

Initializes the scheduler's context.

Parameters

scheduler

The scheduler instance to initialize the context of.

_Scheduler_simple_SMP_Node_initialize()

void _Scheduler_simple_SMP_Node_initialize	(	const Scheduler_Control *	scheduler,
		Scheduler_Node *	node,
		Thread_Control *	the_thread,
		Priority_Control	priority
	)

Initializes the node with the given attributes.

Parameters

	scheduler	The scheduler instance.
[out]	node	The node to initialize.
	the_thread	The user of the node, if RTEMS_SMP is defined.
	priority	The priority of the node to initialize.

_Scheduler_simple_SMP_Reconsider_help_request()

void _Scheduler_simple_SMP_Reconsider_help_request	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Reconsiders help.

Parameters

scheduler	The scheduler instance to reconsider the help request.
the_thread	The thread reconsidering a help request.
node	The scheduler node.

_Scheduler_simple_SMP_Remove_processor()

Thread_Control* _Scheduler_simple_SMP_Remove_processor	(	const Scheduler_Control *	scheduler,
		struct Per_CPU_Control *	cpu
	)

Removes an idle thread from the given cpu.

Parameters

scheduler	The scheduler instance.
cpu	The cpu control to remove from scheduler.

Returns

The idle thread of the processor.

_Scheduler_simple_SMP_Unblock()

void _Scheduler_simple_SMP_Unblock	(	const Scheduler_Control *	scheduler,
		Thread_Control *	thread,
		Scheduler_Node *	node
	)

Unblocks a thread.

Parameters

	scheduler	The scheduler instance.
[in,out]	thread	The thread to unblock.
[in,out]	node	The scheduler node of thread.

_Scheduler_simple_SMP_Update_priority()

void _Scheduler_simple_SMP_Update_priority	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Updates the priority of the node.

Parameters

scheduler	The scheduler instance.
the_thread	The thread of node.
node	The node to update the priority of.

_Scheduler_simple_SMP_Withdraw_node()

void _Scheduler_simple_SMP_Withdraw_node	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node,
		Thread_Scheduler_state	next_state
	)

Withdraws node.

Parameters

scheduler	The scheduler instance to withdraw the node.
the_thread	The thread using the node.
node	The scheduler node to withdraw.
next_state	The next thread scheduler state in the case the node is scheduled.

_Scheduler_simple_SMP_Yield()

void _Scheduler_simple_SMP_Yield	(	const Scheduler_Control *	scheduler,
		Thread_Control *	thread,
		Scheduler_Node *	node
	)

Performs a yield operation for the thread.

Parameters

	scheduler	The scheduler instance.
	thread	The thread to yield.
[in,out]	node	The node of the thread to perform a yield.